Free flow wall cleaner



Feb. 9, 1965 J. HERNDON ETAL 3,163,921

FREE FLOW WALL CLEANER Filed April 2'7, 1962 2 Sheets-Sheet 1 INVENTORS25 1.4%? J AEE/VflO/V /Ace 5. dUEE/V Feb. 9, 1965 L. J. HERNDON ETAL3,163,921

FREE} now WALL CLEANER Filed April 27, 1962 2 Sheets-Sheet 2 UnitedStates Patent Ofitice 3,168,921 Patented Feb. 9, 1965 3,168,921 FREEFLGW WALL CLEANER Luther .i. Herndou and lack 13. Queen, both of Duncan,Okla, assignors to Hallihurton Company, Duncan, kla., a corporation ofDelaware Filed Apr. 27, 1962, Ser. No. 196,719 9 Claims. (Cl. 166-473)This invention relates to a well bore wall cleaner and, in particular,is directed to a cleaner of this type which presents a minimal amount ofresistance to fluid flow past the cleaner.

There are numerous operations and processes performed during thedrilling and completion of a well in which it is desirable to clean thewell bore wall in some manner. It has been conventional to mountscratchers on the exterior of a casing, run the easing into the wellbore, and reciprocate or rotate the casing so that the scratchers abradeor scratch the well bore wall to remove the drilling mud filter cake andthe like from the well bore wall.

Since a Well bore is usually irregular in surface configuration anddiameter it is generally desirable that the scratcher have members whichare flexible in order to conform to the configuration and diameter ofthe well bore. There are numerous types of scratchers having flexibleelements protruding outwardly with their terminal ends adapted to engageand abrade the well bore wall. However, there are certain well boreconditions wherein it is undesirable to abrade or scratch the well herewall with a pointed element even though it is desirable to removethefilter cake from the well bore wall. In these certain conditions,this type of pointed scratcher may remove the filter cake butmay alsoremove an excessive amount of the earth formation which may causecaving-in of part of the formation. 7

It is conventional to circulate the drilling mud during the scratchingoperation in order to carry the material, which has been removed by thescratching, to the surface of the well. Thus the drilling fluid or mudmust be circulated past the scratchers in the annular space between thecasing and the well bore wall. Further, when the casing is beingcemented into the well bore the cement must also flow past thescratchers in a like manner. The abrading elements of many of theconventional scratchers are relatively thick in cross sectional area orare so numerous as to create a substantial restriction to the flow offluid past the scratcher. In numerous situations,,a relatively longportion of well bore wall must be cleaned and therefore numerousscratchers must beprovided on the exterior of the casing. In such asituation, the resistance to fluid flow past thescratehers may beobjectionably high due to the cumulative effect of the numerousscratchers used.

1 Accordingly it is an object of this invention to provide a novel formof well bore cleaner adapted to be mounted on a well pipe whereintheelements provided for cleaning the wall of the well bore present aminimal restriction to the flow of fluid past the cleaner and theseelements.

Another object of this invention is to provide a novel form of well borewall cleaner wherein projecting elements for cleaning the well bore wallare provided which engage. the well bore wall in a line contact ratherthan a point contact to accomplish cleaningof the wall withouobjectionably gouging or abrad'ing the .wall;

A further object of this invention is to provide a novel form of wellbore wall cleaner wherein loop shaped elements are provided having.arcuate portions which combine to define a circle for cleaning thewellbore'wall. A still further object is to'provide such acleaner wherein:the loop shaped elements may pivot toward the casing individually ortogether to assume the particular configuration or size of that portionof the well bore.

A more specific object of this invention is to provide a well bore wallcleaner wherein loops are pivotally mounted on a collar adapted to bemounted on a well pipe and such loops overlap one another to definesubstantially the circumference of a circle the size of which is variedas the loops are pivoted.

Other and more detailed objects and advantages of this invention willappear from the following description and the accompanying drawings.

In the drawings:

FIGURE 1 is a plan view of the well bore wall cleaner of this invention.

FIGURE 2 is a fragmentary sectional elevation taken substantially on theline 2-2 as shown in FIGURE 1.

FIGURE 3 is a fragmentary sectional elevation from the inside of thecollar of this invention talcen substantially on the line 3-3 as shownin FIGURE 2.

FIGURE 4 is a fragmentary sectional plan view taken substantially on theline 4-4 as shown in FIGURE 2.

FIGURE 5 is a sectional elevation view similar to FIG- URE 2illustrating the loops of the cleaner in their upwardly pivotedposition.

FIGURE 6 is a'fragmentary plan view illustrating the overlappingmounting of adjacent loops.

FIGURE 7 is a perspective View showing a modifiedform of this inventionand illustrating'the device in a hinged-open position for mounting sameon a well pipe. FIGURE 8 is a perspective view of the device ofthisinvention mounted on a well pipe with the loops pivoted upwardly fromtheir lowermost position. FIGURE 9 is a perspective view of one of theloops of the modified form shown in FIGURE 7. Referring now to thedrawings, the well bore wall cleaner, generally designated 16, isprovided with. a generally cylindrical collar designated 11.. Collar 11may be a solid cylindrical collar adapted to he slipped onto a well pipeor the collar may be comprised of two semi-cylindrical collars 12 and 13hinged together by hinges 14 and 15. The hinge pm of hinge 14 or hinge15 may be removed and the semi-cylindrical collars 12 and 13 pivoted toan open position for laterally applyingthe cleaner 10 to a well casing,tubing or pipe. The function and configuration of collar 11 issubstantially the same whether it is a solid collar or ahinged collar asshown. The collar 11 is provided with a circumferential bead 16 which isgenerally V-shaped and projects outwardly from the major cylindricalportion of the collar. Since bead 16 is V-shaped it is comprised of adownwardly and outwardly projecting conical portion 17 and an upwardlyand outwardly projecting conical portion 18. An internal annular hollowportion 19 is formed by the bead. The upper conical portion 17 of thebead 16 is provided with a series of apertures 26 which are relativelyuniformly spaced around the entire circumference of the bead 16, thisspacing being interrupted and somewhat nonuniform at the hinges 14 and15. i The well bore cleaner 10 is provided with a plurality of cleanerelements, generally designated 21, for engaging and cleaning the wellbore wall as hereinafter described. Each of the cleaner elements L l-hasa loop portion comprised of a pair of outwardly projecting arms 22 and23 joined at their outer extremities by a circumferentially extendingarcuate portion 24. As may be seen in the drawings, the arms'22 and 23and arcuate portion 24 all lie in approximately a single plane, i.e.,the plane of the loop, and this plane'may be either perpendicular to orat an angle to the axis of the collar 11, as will hereinafter bedescribed; i

' Each of the cleaner. elements 21' isfialso provided with a pair ofmounting bases (not numbered) for mounting each arcuate portion 24 isjoined to an end piece 27 which extends outwardly through a separateaperture 2%. As shown in the drawings, each mounting base has itsconnecting piece 25 extending through one aperture 20 and its end piece2'7 ex tending through a separate aperture 20. Although it is preferredand is shown in FIGURES 3, 4 and 6 that the connecting piece 25 and endpiece 27 of each mounting base extend through adjacent apertures 20 itwill readily appear to those skilled in the art that by providing alonger lateral piece 26 the connecting piece 25 and end piece 27 mayextend through non-adjacent apertures 28 without altering or affectingthe function of the mounting base. 1

The arms 22 and 230i each cleaner element 21 converge inwardly towardeach other such that the connecting pieces 25 joined to' each of thearms pass through adjacent apertures '20. The lateral piece 26 of eachmounting base extends circumferentially away from the other mountingbase of the same cleaner element 21. Each cleaner element 21 has itsconnecting pieces 25. extending through a pair of apertures adjacent tothe pair of apertures through which the connecting pieces of nextadjacent cleaner element 21 extend. Since apertures 20 are spacedrelatively close togetherand since arms 22 and 23of each cleaner element21 converge inwardly toward each other, the arm 22 of one cleanerelement 21 overlaps the arm 23 of the next adjacent cleaner element 21.Likewise, the arcuate portion 24 of each cleaner element 21 overlaps thearcuate portions 24 of both of the adjacent cleaner elements 21 for asubstantial arcuate distance. All of the arms 22' and 23fand arcuateportions 24 on the wall cleaner 10 lie substantially in a planeperpendicular to the axis of the collar 11 when the cleaner elements 21are in their inflexed and unpivoted position shown in FIGURES l and 2.Each of the arcuate portions 24 preferably have a radius of curvatureequal to the radius from the axis of the collar 11 to the outerextrernities of the arms 22 and 23 such that the arcuate portions 24 ofall of the cleaner elements 21 combine to define substantially a circleas is shown in FIGURE 1. The circumference of this defined circle iscontinuous since overlaps the next adjacent arcuate portions.

The mounting bases of each cleaner element 21 cooperate with the edgesof the apertures and with the bead16 to support each cleaner element inthe radially projecting position shown in FIGURES 1 and 2 but alsopermit each cleaner element to be pivoted upwardly as shown in FIGURE 5.In the position shown in FIGURE 2, each end piece 27 and connectingpiece 25 engages the lower edge 28 of the aperture 20 through which itpasses and the lateral piece 26 engagesthe inner surface of the upperconical portion 17of the bead 16 thereby supporting the loop of thecleaner element in the radially projecting position. Since two mountingbases (one from each of the adjacent cleaner elements 21) are positionedin each pair of apertures 26 the connectingpieces 25, end pieces 27, andlateral pieces 26 may actually engage such pieces of the other mountingbase rather than engaging the edge 28 of an aperture 20 or the innersurface of the conical portion 17. Whether the connecting piece, lateralpiece and end piece of a particular mounting base are supported byportions of the head 16 or by like pieces of another mouhtihgbase is ofno consequence since in either manner the desired support is provided.The apertures 20 are substantially greater in size than the crosssectionoflthe connecting pieces 25 d and end pieces 27 so that each of theelements 21 is free to pivot upwardly as shown in FIGURE 5. The upperlimit of pivoting is limited only by the lateral pieces 26 engaging theinner surface of the lower conical surface of a well pipe when thecleaner 10 is installed on a well pipe, the downwardly bent portions 30serve to prevent such movement when the cleaner 10 is not on a wellpipe.

The modified form of well bore wall cleaner, generally designated 1%,shown in FIGURE 7 has a hinged cylindrical collar generally designated11a. which is substantially the same as collar 11 heretofore described.Collar 11a has a circumferential bead 16a provided with apertures Ztlasimilar to the bead 16 and apertures Zi) of cleaner 10. The cleanerelements 21a have mounting bases of a configuration the same or similarto that previously described but the loop portion of the cleaner element21a is modified from the loop portion of cleaner 21. Thecircumferentially extending arcuate portion 24a of cleaner element 21ais similar to arcuate portion 24 3 but may be longer so that the amountof arcuate over- In operation, the well bore wall cleaner 10 or 10a is'positioned on a well casing, tubing or pipe 9 as shown in FIGURE 8. Themovement of the cleaner It), or 10a along the well pipe 9 is limited byproviding stop lugs or collars (not shown) on the well pipe in aconventional manner, or the cleaner'may be aihxed to the well pipe as bywelding. Although it is not essential, it is preferred that the wellbore cleaner 10 or 10a be positioned on the well pipe near a centralizerso that the cleaner elements 21 or 21a will not be compressed flatagainst one side of the well bore. While the'well pipe 9 is run througha casing or portion of the well bore which is of smaller diameter thanthe diameter of the circle formed by the arcuate portions 24 or 24a, thecleaner elements 21a are pivoted upwardly as shown in FIGURE 5 toconform to the size of the casing or well bore. When the well pipe 9 isreciprocated within the well bore, the arcuate portions 24a engage thewell bore wall in a line contact and clean the drilling mud filter cake,etc., from the well bore wall. If the well bore is of a smaller diameterthan the circle formed by the arcuate portions 24 or 24a (as willnormally be the situation) the upward movement of the well pipe 9 willcause the arms 22 and 23 or 22a and 23a to be flexed downwardly toreduce the diameter of the circle-formed by the arcuate portions 24 or24a.

It is preferred to make the cleaner elements 21 or 21a of a relativelyrigid and resilient material such as steel wire although other materialsmaybe used. ,With a relatively rigid and resilient cleaner element 21 or21a the arcuate portion 24. or 24a will be adequately supportedr i I Ipointed cleaning elements that may .objectionably gouge or abrade thewell bore wall. Further, it may be seen that the cleaner elements of ourwell bore cleaner provide a full 360 contact with the wellbore Wall forcleaning of same and yet the cleaner elements present a very minimalrestriction to the flow of fluid past the cleaner.

Having fully described our invention, it is to be understood that we donot wish to be limited to the details herein set forth orto the,detailsillustrated in the drawings, but our invention is of the fullscope of the appended claims.

We claim:

11 In a well bore cleaner, the combination of: a collar adapted to bemounted on the exterior of a well pipe, a plurality of cleaner elementscircumferentially spaced around and mounted on said collar, each saidcleaner element being comprised of a relatively rigid material andhaving a loop portion extending outwardly from said collar, each saidloop portion having a pair of arms projecting outwardly from said collarand a circumferentially extending arcuate portion joining the outermostextremities of said pair of arms, and the said arcuate portions ofadjacent cleaner elements overlapping for a substantial arcuate distanceto form substantially a full circle for engaging and cleaning the wellbore.

2. In a well bore cleaner, the combination of: a collar adapted to bemounted on the exterior of a well pipe, a

arms projecting outwardly from said collar and a circumferentiallyextending arcuate portion joining the outermost extremities of said pairof arms, each of said arms being curved, and the said arcuate portionsof adjacent cleaner elements overlapping for a substantial arcuatedistance to ,form substantially a full circle for engaging and cleaningthe well bore.

i 3. In a well bore cleaner, the combination of: a collar adapted to bemounted on the exterior of a well pipe, a plurality of, cleaner elements,circumferentially spaced around and' mounted on said collar, each saidcleaner elementibeing comprised of a relatively rigid and resilientmaterial and having a loop'portion extending outwardly from said collar,each said loop portion having a pair of for engaging and cleaning thewell bore.

4. In a well bore cleaner, theco'mbination of: a collar adapted to bemounted on the exterior of a well pipeQa plurality of cleaner elementscircuinferentially spaced around and mounted on said collar, each saidcleaner element being comprised of a relatively rigid and resilientmaterial and having a loopportion extending outwardly from said collar,each said loop portion having a pair of arms projecting outwardly fromsaid collar 'and a cir-- cumferentially extending arcuate portionjoining the outermost extremities of said pair of arms, said arms .beingi l relatively small in cross-sectional area for presenting a minimalresistance to fluid flow past said-arms, and the said arcuate portionsof adjacent cleanerelements over lapping for a substantial arcuatedistance to form sub-.

stantially a full circle for engaging and cleaning the well bore. t

5. In a well bore cleaner, the combination of: a

collar adapted'to be mounted "on thetexteri'or ofa well pipe, aplurality of clfeanerfelements 'circumferentially ,spaced around'saiclcollar, each said cleaner element.

being comprised of a relatively rigid and resilient material and havinga loop portion extending outwardly from said collar, each of saidcleaner elements being pivotally mounted on said collar for freemovement of said loop portion from a radially extending position to anupwardly and outwardly extending position, each said loop portion havinga pair of arms projecting outwardly from said collar and acircumferentially extending arcuate portion joining the outermostextremities of said pair of arms, and the said arcuate portions ofadjacent cleaner elements overlapping for a substantial arcuate distanceto form substantially a full circle for engaging and cleaning the wellbore.

6. In a well bore cleaner, the combination of: a collar adapted to bemounted on the exterior of a well pipe and having internally hollowmeans, said hollow means having apertures therethrough incircumferentially spaced relationship around said collar, a plurality ofwire cleaner elements circumferentially spaced around said collar, eachsaid cleaner element having a pair of base portions and a loop joiningsaid base portions; each said base portion having means extendingthrough one of said apertures, circumferentially within said hollowmeans, and outwardly through another of said apertures for pivotallysupporting the cleaner element on said collar; each said loop portionhaving a pair of arms projecting outwardly from said collar and acircumferentially extending arcuate portion joining the outermostextremities of said pair of arms, and the said arcuate portions ofadjacent cleaner elements overlapping for a substantial arcuate distanceto form substantially a full circle for engaging and clean ing the wellbore.

7. 'In a well bore cleaner, the combination of: a collar adapted to bemounted on the exterior of a well pipe and having a circumferentialextending and outwardly projecting hollow bead, said hollow bead havinga plu-.

rality of circumferentially spaced apertures therethrough, a pluralityof wire cleaner elements circumferentially spaced around said collar,each said cleaner element having a pair of base portions and a loopjoining said base portions; each said base portion having meansextending through one of said apertures, circumferentially within saidhollow means, and outwardly through another of said apertures forpivotally supporting the cleaner element of said collar; and said loopof each cleaner element having an outwardly projecting arm joined toeach of said base portions and a circumferentiallyextending arcuateportion joining the outermost extremities of said two arms, each saidarm and .a portion of the arcuate portion joined thereto overlapping theadjacent arm and a portion of the arcuate portion of the loop of thenext adjacent cleaner element, the said'arcuate portions of adjacentcleaner elements overlapping for a substantial arcuate distance to formsubstantially a full circle for engaging and cleaning the well bore.

8. Ina well bore cleaner, the combination of: a collar adaptedto bemounted on the exterior of a well pipe and having acircumferentialextending and outwardly projecting, hollow bead, said hollow bead havinga plurality of circumferentially spaced apertures therethrough, aplurality of wire cleaner elements circumferentially spaced around saidcollar, each said cleaner elernent having a pair of base portions andaloop joining said base portions; said base portions each having aconnecting portion, an end portion, and alateral portion joining saidconnecting portion to 'said end portion; eachx 'said base portion havingthe said connecting portion outwardlythrough anothenof said aperturesfor-pivotally- 'supporting the cleaner elementonsaid collar for freemovement of the loop portionfrom a radially projecting position to anupwardly and outwardly projecting posioutwardly projectingarm joined toeach of said connecting portions and a circumferentially extendingarcuate portion joining the outermost extremities of said two arms, eachsaidfar'm and ,a portion of the arcuate portion joined theretooverlapping the adjacent arm and a portion of the arcuate portion of theloop of the nexttadjacent cleaner element, the said arcuate portions ofadjacent cleaner elements overlapping for a' substantial arcuatedistance to" form substantially a ,full circle for engaging and cleaningthe well bore and the upward pivoting of all of the cleaner elementsserving to reduce thefdiameter I of such defined circle.

9.- The combination of claim 8 wherein the said arms '7 of the cleanerelements arecurved for permitting the loop portion to resilientlycollapse.

I References Cited in the file of this patent UNITED STATES PATENTS2,683,491 Gassaway". July 13, 1954 Wright et an. t Mar. 11, 195s

1. IN A WELL BORE CLEANER, THE COMBINATION OF: A COLLAR ADAPTED TO BEMOUNTED ON THE EXTERIOR OF A WELL PIPE, A PLURALITY OF CLEANER ELEMENTSCIRCUMFERENTIALLY SPACED AROUND AND MOUNTED ON SAID COLLAR, EACH SAIDCLEANER ELEMENT BEING COMPRISED OF A RELATIVELY RIGID MATERIAL ANDHAVING A LOOP PORTION EXTENDING OUTWARDLY FROM SAID COLLAR, EACH SAIDLOOP PORTION HAVING A PAIR OF ARMS PROJECTING OUTWARDLY FROM SAID COLLARAND A CIRCUMFERENTIALLY EXTENDING ARCUATE PORTION JOINING THE OUTERMOSTEXTREMITIES OF SAID PAIR OF ARMS, AND THE SAID ARCUATE PORTIONS OFADJACENT CLEANER ELEMENTS OVERLAPPING FOR A SUBSTANTIAL ARCUATE DISTANCETO FORM A SUBSTANTIALLY A FULL CIRCLE FOR ENGAGING AND CLEANING THE WELLBORE.